This invention relates to a ringless spinning frame, wherein a sliver is taken up from each of a plurality of sliver cans disposed above a body of the spinning frame and fed through a sliver guide conduit into the spinning frame body from the back side of the corresponding spinning unit.
Heretofore, in order to provide very large packaged cans and to smoothly supply a sliver from each can, disposed above a body of a spinning frame, to a corresponding spinning unit without applying strong tension to the sliver, it has been proposed to provide the spinning frame with a sliver guide conduit, one for each sliver, which extends downwardly from near the sliver can into the spinning frame body and passes therethrough along the back of the corresponding spinning unit and opens at a position below the spinning unit. A ringless spinning frame of this type is described in U.S. Pat. No. 3,816,991 entitled "Method and Device for Supplying Sliver to A Spinning Machine" and assigned to the same assignee as the present application.
With this type of ringless spinning frame, the body is normally covered to arrest noise, and therefore the interior thereof is raised in temperature due to heat produced in the spinning units when components of the spinning unit, such as, a rotor, a spindle and a belt, are driven at high speed. The produced heat would cause a temperature difference in the order of about 10.degree. to 20.degree. C. between the interior and the exterior of the spinning frame body. With respect to the sliver fed within the sliver guide conduit, for example, in the case of 20 counts, it takes about 6 minutes to pass through the guide conduit portion within the spinning frame body. Therefore, during this time period, the sliver moving in the guide conduit will be heated due to the high temperature of the frame body interior. This causes moisture in the sliver to be evaporated and therefore the sliver becomes over dried, resulting in a poor quality of spun yarn, and especially in a decreased yarn strength.
Furthermore, it is to be noted that the sliver as well as air having a low temperature, which is substantially equal to that of the spinning frame exterior, will be fed into the sliver guide conduit. This causes a temperature of the outer surface of the guide conduit portion within the spinning frame body to be decreased and air surrounding the outer surface to attain its dew point due to the high temperature of the body interior, thereby providing water drops on the outer surface of the guide conduit. Apparently, the water drops have bad influences upon structures within the spinning frame body.